3-(morpholinoethoxy)pyridazines

ABSTRACT

THERE IS DESCRIBED NEW CHEMICAL COMPOUNDS OF THE GENERAL FORMULA:   3-(Y-N(-Z)-(R2)-O-),4-R1,6-AR-PYRIDAZINE   WHERE: R1 IS A LOWER ALKYL SUBSTITUENT PARTICULARLY METHYL; R2 IS   -(CH2)N- OR -CH(-CH3)-CH2-   N IS 2,3 OR 4; AR IS HALOGEN OR A LOWER ALKOXY SUBSTITUENT PARTICULARLY METHOXY OR A CYCLE PARTICULARLY PHENYL, NAPHTHYL, THIENYL; Y AND Z REPRESENT LOWER ALKYL GROUP FUNCTIONS, THESE GROUPS BEING ABLE TO BE CYCLIZED SO AS TO FORM WITH THE ATOM OF NITROGEN, A HETEROCYCLIC RADICAL SUCH AS MORPHOLINYL-, METHYLPIPERAZINYL, AND NON-TOXIC ACID SALTS THEREOF, THE SAID COMPOUNDS HAVING PSYCHOTROPIC ACTIVITY IN THE FIELDS OF ANALGESIA AND ANTI-NEUROTIC AND ANTI-ANXIETY TREATMENT OF MAMMALS INCLUDING MAN.

United States Patent US. Cl. 260247.5 R 2 Claims ABSTRACT OF THE DISCLOSURE There is described new chemical compounds of the general formula:

where:

R is a lower alkyl substituent particularly methyl; R2 is n is 2, 3 or 4;

Ar is halogen or a lower alkoxy substituent particularly methoxy or a cycle particularly phenyl, naphthyl, thienyl; Y and Z represent lower alkyl group functions, these groups being able to be cyclized so as to form with the atom of nitrogen, a heterocyclic radical such as morpholinyl-, methylpiperazinyl, and non-toxic acid salts thereof, the said compounds having psychotropic activity in the fields of analgesia and anti-neurotic and anti-anxiety treatment of mammals including man.

The present invention relates to a new family of chemical compounds of which the members are distinguished by their psychotropic action, and particularly analgesic, anti-inflammatory, potentiating of barbiturates and antineurotic.

This family has the general formula:

R1 Ar- O(Rz)N N-N z where: R =lower alkyl with l-3 C, particularly methyl;

3,825,540 Patented July 23, 1974 TABLE L-LIST OF THE SYNTHESIZED COMPOUNDS I Y Ar- O-(CH ),-N\

Code Ag AI R; n Y-Z 614 B-Naphthyl-.. CH: 2

618 a-Naphthyl. CH; 2 Same as above 619 B-Naphthyl--. CH3 3 Do.

correspond to the branched chain.

It seems that, although the invention is not limited by any theory, the psychotropic action of these compounds is connected with the simultaneous presence of the group R (alkyl in position 4 on the pyridazine nucleus) and, in position 3, of the nitrogenated group of which the nitrogen is separated from the pyridazine nucleus by two or three atoms of carbon.

The invention also relates to a process for the preparation of these compounds by the reaction of a 3-chloropyridazine with an alcoholate.

According to a subsidiary characteristic, the alcoholate considered is prepared by the action of powdered sodium on the corresponding alcohol in a reaction mixture diluted by means of anhydrous tetrahydrofurane.

Set forth in the table below is the physical properties of a certain number of compounds, of which the preparation will be described hereinafter in detail in the examples.

TABLE IL-PHYSICAL CON STANTS OF THE SYN THESISED COMPOUNDS Code Aspect F. Solubility 614 White powder... 192 (H01) Cold water 618 Pink powder 193 (2 H01) Cold water on Beige powder-.. 171 (2 H01) {ggf fi g t 3 Operational method (7) Preparation of u-hydroxy tit-methyl 'y-keto d-naphtylbutyric acid-Introduce 70 ml. (1 mole) of pyruvic acid into a 2 litre conical flask. Neutralise exactly with a 4 0.20 mole) of hydrated hydrazine and 100 ml. of butanol. Distil the solution obtained: the azeotropic water-butanol distils over at 925, the butanol at 117. At this stage, stop the distillation and evaporate the excess butanol under vacuum. A light yellow residue is obtained which 20% solution of KOH (approx. 350 m1.) whilst cooling 5 o and stirring. Then add 170 g. (1 mole) of 2-methyl naphthe E W 'naphthyl) fpyndazlPone' F2280 tylketone, then a solution of 70 g. of KOH in one litre of To th1s resldue add 130 crystalhsable 3 o methanol. Add again 1 litre of methanol to homogenise and concentrated Bung a 110 the reaction medium. for one hour anda half. At the end of this time tipthe Leave to rest for two days at ambient temperature (do sol-utionobtamed into some crushed 1ce (approx. 300 g not place in a cold chamber because the methylnaphtyl The pyrrdazone precipitates. It is pale yellow. The pyridketone precipitates) azone formed is filtered washed with water and recrystal- After this time neutralise exactly to pH 7 with H 80 hsed P 10 N (approx 120 Whilst cooling evaporate the The yield obtalned after recrystallisation: 30 g., or 70%. methanol under vacuum. Acidity with H 80 10 N 8- (approx. 300 ml.). Add water in a sufiicient quantity to PrfiParaliloIl of 3411110) 4'methyl P hY PY dissolve K 80 formed and extract with ether by three Of Pocla to a flask f portions (300100-100 ml.). Wash the ethereal layer nlng 30 g. (0.127 mole) of the pyridazone described with 100 ml. of water and extract with a solution of 10% P the mlxtul'e for 1% hours under reflux potassium bicarbonate (500450 1 ring from time to time. The solution adopts a dark red Wash the bicarbonated fraction with a little ether and 60101113 Then P9 it Into Ice PP 300 acidity in an ice bath with n so 10 N (approx. 105 ml.). and add t 501M109 9 a; 9 111 125 of Water- It A white precipitate is obtained which is filtered, washed forms a P preclpltate whlch filtered and well y q with water and dried. It is recrystallised in alcohol. Wlth Waterp f Obtalned 1S fY 111 The yield Obtained ft recrystallisation; 46 g or 13% 25 methanol. The yield obtained after recrystallisation: 27 g., F=l. or 81%. F=167.

(2) Preparation of 4-methyl 6-1'1aphthyl pyridazone, In a similar manner the chloropyridazines necessary for Introduce 46 g. (0.18 mole) of the preceding acid into a the synthesis of the compounds Agr 600, 601, 602, 606, 250 ml. flask. Dissolve it in hot butanol. Then add 9 g. 607, 608, 613, 618, 622, 6 54 and 668 have been prepared. 30 The constants of the new fi-acyllactic acids, hydroxy- Th th 1h ldid hd M (1 rated. itim tiii fiiiiiiiii kit oiifiiiii 11 not miiii is it pyndazfmnes F and chbmpyndazmes cuperated. shown 1n the following tables:

B-AOYLLAOTIC ACIDS Analysis, percent Calculated Found Recrystallisation Yield, Formulae F. solvent percent 0 H C H 24 l E 1 CtHt 5045 470 4982 405 s C-CHr-C-OH OOH CH, Alcohol at 4o...-.= 20 69.75 5.46 69.34 5.34 CO-OHz--OH OOH (H) (311; 122 Alcohol at 45--..'; 28.5 69. 75 5. 46 69.17 5. 41 --CCH:(l3-OH CHLOROPYRIDAZINES Analysis, percent Calculated Found Recrystallisation Yield, Formulae F. solvent percent 0 H N C H N 127 Methanol 89 61.41 4.72 11.93 1.1 11.

189 Tetrahydroturane...

TABLEC0nt1nued Analysis, percent Calculated Found Recrystallisatlon Yield, For ulae "F. solvent percent 0 H N C H N 132 Methanol 75 55.23 3.37 11.57 55.07 3.50 11.65

N-N C1 I-l 135 do... 88 51.30 3.35 13.20 51.20 3.39 13.0

I 167 .....do 81 70.72 4.35 11.0 70.22 4.33 11.0

114 .....d0 82 70.72 4.35 11.0 70.57 4.53 11.10 Cl C? Cl 142 ...-.do 63.5 63.00 3.39 14.69 62.19 3.79 14.43

HYDROXY PYRIDAZINONES Analysis, percent Calculated 3 Found Recrystallisa- Yield, Formulae F. tion Solvent percent 0 H N C H N CH, OH 147 Alcoh01at50 92 64.69 5.92 13.72 64.51 5.79 13.87 W

OH; OH 216 Isopropano1-.... 95 61.52 6.02 11.96 61.40 5.05 11.87

OH; OH 188 .....do....: 90 55.35 4.64 11.73 55.65 4.88 11.95

OH; OH 172 ..-..do 83 55.35 4.64 11.73 56.57 4.60 12.13

OH; OH 186 :'.:..do 73 51.40 4.79 13.32 51.67 4.65 13.07

TABLE-C0n-tlnued Analysis, percent Calculated Found Recrystalllsa- Yield, Formula "F. tlon Solvent percent 0 H N C H N 0 200 .'-....d0 85 70.84 5.53 11.03 70.97 5.63 11.00 on I N-H CH: 1

CH; 011 Liquid.--.;---.. Gummy 1 M W 3 I 05H: OH 162 Isopropanol..... 97 66.03 6.47 12.84 66.10 5.51 12.85

PYRIDAZONES Analysis, percent Calculated Found Recrystallisetlon Yield, Formulae solvent percent 0 H N C H N 254 Isopropanol 93.5 66.34 6.03 12.89 64.06 5.98 12.85

218 Methanol 82 59.77 4.11 12.69 59.87 4.21 12.71

(I31 220 Isopropanol'...-.-: 86 59.87 4.11 12.69 59.73 4.22 12.51

229 Methan0l----:.-".-.-..: 90 59.87 4.11 12.69 59.65 4.22 13.03

I l 229 Aleohol95 80 56.22 4.19 14.57 55.99 4 15 14.38 G

0 228 Isopropanol.....-.-: 82 76.24 5.12 11.85 75.56 4.89 11.90

' TABLEComtinued Analysis, percent Calculated Found Recrystallisation Yield, Formulae F. solvent percent H N C H N 0 H; 141. .do. 95 71.98 6.04 13.99 71.41 6.09 14.11

EXAMPLE 1 Recrystallisation in isopropanol, C H O N M=342;

Preparation of 3-amino-ethoxy-4-methyl 6- (paramethoxy) phenyl pyridazine Operational metho-d.-Weight 0.05 m0le1.15 g. of sodium into dry toluene. By heating and vigorous stirring, the sodium is separated into particles. Decant the toluene and add ml. of dry tetrahydrofurane. \Add slowly, with magnetic stirring 0.05 mole-3.06 g.3.03 ml. of ethanolamine. In order to accelerate the reaction, heat the solution on a water-bath, whilst continuing to stir.

Then add to the alcoholate, 0.05 mole1l.75 g. of 3- chloro 4-methyl 6(p-methoxy)-phenyl pyridazine in solution in ml. of dry tetrahydrofurane. Sodium chloride separates after 7-8 hours of heating under reflux on the waterbath.

Filter NaCl and add a little anhydrous ether to the filtrate. Pass through gaseous HCl. There is obtained 13.6 g.91% of hydrochloride, recrystallising in 95 alcohol. E: 147, resolidification, then F=218. Extraction of the base: the base (Agr 601) may be isolated in the following manner: dissolve 0.005 mole (1.48 g.) of hydrochloride in 10 ml. of distilled water. Add 0.01 mole (l g.) of potassium bicarbonate. The solution becomes limpid, yellow. After several moments, the base is separated in the form of a yellow oil, being deposited at the bottom of the container.

Extract with two portions of chloroform. Dry over anhydrous magnesium sulphate and evaporate the solvent. There remains a yellowish oil which after several moments crystallises.

Fine white power, insoluble in water, ether, soluble in chloroform.

Yield: 06 g.-%.

Centesimal analysis, C14H17O2N3:

Cale. (percent): C, 64.84; H, 6.60; N, 12.60. Found (percent): C, 64.39; H, 6.60; N, 14.50.

EXAMPLE 2 Preparation of N-methyl-piperazine 3-ethoxy-4- methyl fi-(paramethoxy) phenyl pyridazine Heat 0.113 mole2.8 g. of sodium in dry toluene. When the solvent commences to boil, stir vigorously; the sodium is separated in particles. Decant the toluene and add ml. of dry tetrahydrofurane. Add gradually 0.113 mole-16.3 g. of N-methylpiperazinoethanol, then heat on the water-bath until dissolving of the sodium.

Then add, in small fractions, 0.113 mole26.5 g. of 3- chloro 4-methyl 6- (paramethoxy) phenyl pyridazine in solution in 50 ml. of tetrahydrofurane. The sodium chloride separates after heating for seven to eight hours on the water-bath with constant stirring. By the addition of distilled water, the sodium chloride dissolves, the base crystallises. Filter and dry.

Yield: 29 g.76%.

Formation of hydrochloride-Dissolve 0.059 mole 22 g. of base in the minimum of hot isopropanol. Warm, then add drop by drop the equimolar quantity of concentrated hydrochloric acid. Start the crystallisation by the addition of anhydrous ether.

Yield: 20 g.-%.

Recrystallisation in alcohol.

White powder, soluble in water.

Centesimal analysis, C H O' N Cl:

Calc. (percent): C, 60.3; H, 7.13; N, 14.8. Found (percent): C, 61.0; H, 7.15; N, 14.4.

EXAMPLE 3 Preparation of morpholino 3-propoxy 4-methyl 6- (paramethoxy) phenyl pyridazine Same method of operation as previously. Proportions: 1.4 g. (0.057 mole) of Na, 15.9 g. (0.057 mole) of morpholino-l-propanol and 13.25 g. (0.057 mole) of 3- chloro 4-methyl 6-(paramethoxy) phenyl pyridazine.

The base is extracted with ether. Drying on anhydrous MgSO It is filtered and the ether is evaporated on a rotary evaporator. The base is recrystallised in isopropyl alcohol. Recrystallisation is very rapid with the use of a heated funnel.

Formation of hydrochloride-Gaseous HCl is passed through the solution containing the base dissolved in acetone. We obtain 5 g. of hydrochloride which are recrystallised in 95 alcohol. F=113.

EXAMPLE 4 Preparation of morpholino 3-(2-propoxy) 4-methyl Same method of operation as previously. Proportions: 2.8 g. (0.113 mole) of Na, 15.9 g. (0.113 mole) of 2- morpholinopropanol, 26.5 g. (0.113 mole) of 3-chloro 4-methyl G-(paramethoxy) phenyl pyridazine. 6-(paramethoxy) phenyl pyridazine After formation of the base and dissolving of the NaCl in water, the base is distilled under motor vacuum.

Yield-10 g. of base are obtained, that is 27% with respect to the starting material, which distills under '3 mm. Hg between 255 and 265.

Formation of hydrochloride-Gaseous HCl is passed through the solution containing the base dissolved in acetone. 7.5 g. of hydrochloride are obtained, that is 70% with respect to the base. F=222. Recrystallisation in isopropanol.

EXAMPLE 5 Preparation of 3-morpholinopropoxy 4-methyl '6-phenyl pyridazine Weigh 0.2 1 mole (4.83 g.) of sodium into toluene. By heating and vigorous stirring the sodium is divided into small particles. Decant the toluene and add to the so- '1 1 dium 100 ml. of dry tetrahydrofurane- =Add gradually 0.21 mole (30.5 g.) of morpholinopropanol. To accelerate the reaction, heat on the water-bath whilst stirring magnetically for about 7 hours.

Then add the alcoholate 0.21 mole ('43 g.) of chloropyridazine in solution in 60 ml. of dry tetrahydrofurane. The sodium chloride separates after heating under reflux on the water-bath for 7 to 8 hours.

After this time, add a sufficient quantity of Water to dissolve the sodium chloride and extract the base with 2 to 3 portions of ether. The ethereal extracts are dried over anhydrous magnesium sulphate and evaporated under vacuum with the pump. The oily residue crystallises by the addition of a previously obtained crystal. The yield is 92.7%

EXAMPLE 6 Preparation of 3-(morpholinoethoxy) '4-methyl 6-naphthyl pyridazine 12 the response of the latter after the injection of molecules which have appeared to be the most active. For each one the exploration comprised a minimum of five animals. This is Table IV as follows:

1 Slow waves. 2 minutes.

Finally, in Table VI below, there is given for several of the compounds considered the result of the test of the action on isolated ileum. This Table VI reads as follows:

TABLE VI.ACTION UPON ISOLATED ILEUM (RABBIT, GUINEA PIG) Antagonism upon hypertony Upon hypotony Nicotin Sero- Hlsta- Brady- Adren- Produet Tonus Maxiton toniu min dinin Acetyl AET BaClr KC] alln ous stirring the sodium is separated into small particles. Decant the toluene and add to the sodium 55 ml. of dry tetrahydrofurane. Then slowly add 15.4 g. (0.106 mole) morpholine ethanol. Heat on the oil bath at 110 whilst stirring magnetically.

After this time add to. the cooled mixture 27 g. (0.106 mole) of 3-chloro 4-methyl G-naphthyl pyridazine in solution in '30 ml. of dry tetrahydrofurane. Heat for 7 hours on the oil bath at '1 10 whilst stirring magnetically. Then add some water in a suflicient quantity to dissolve NaCl formed (approx. 500 ml.) and extract with three portions of ether (200--1O0-1 00 1111.). Wash the ethereal phase with water, dry it on anhydrous 'MgSOi; and evaporate the ether under pump vacuum. The oily residue obtained crystallises at the end of one night.

Yield: 3335 g., or 91%.

(b) Formation of hydrochloride:

Agr 618: Obtained as Agr 614 from some 3-chloro 4- methyl 6-'(1'-naphthyl) pyridazine.

Agr 6'19: Prepared as Agr 614 from 3-morpholine propanol and 3-chloro 4-methyl '6-(2'-naphthyl) pyridazine.

By way of example, there is given in the following Table IH the measurement of the dilferent manifestations of the action on the central nervous system of the compounds claimed in this division of the application. Therefore Table III reads as follows:

TABLE IIL-ACTION UPOMggTRAL NERVOUS SYSTEM set forth in the preceding table.

The stereotaxic study of the different central areas of the rabbit with Monnier and Gangloff apparatus, shows It must be noted that in the test known as the writhing test, the DE 50 of certain of the aforementioned products is in the order of 2 5 to 100 mg./kg. Therefore, for the product designated by the code number Agr 6 06, the DE 50 in ing/kg. per bone is 25150. For the product Agr 607, it is 50 and for the product 609 it is 100.

In conclusion, the indications of the products according to the invention are as follows:

(a) analgesia in all medical indications, analgesia in surgical indications, analgesia and neuroplegia (neuroleptanalgesia) and anesthetic potentiation in anesthesia.

(b) anti-neurotic and anti-anxiety action (absence of indication in psychoses due to inverse hippoca-mpic activity from that of the anti-psychotics, chloropromazine, reserpine, haloperidol, which favour after-discharges but synergic of tranquillisers) 1. A compound of the formula:

wherein Ar is alpha or beta naphthyl or non-toxic acid salts thereof. 

